mirror of https://gitee.com/openkylin/linux.git
27 lines
1.2 KiB
Plaintext
27 lines
1.2 KiB
Plaintext
PCI bus bridges have standardized Device Tree bindings:
|
|
|
|
PCI Bus Binding to: IEEE Std 1275-1994
|
|
http://www.firmware.org/1275/bindings/pci/pci2_1.pdf
|
|
|
|
And for the interrupt mapping part:
|
|
|
|
Open Firmware Recommended Practice: Interrupt Mapping
|
|
http://www.firmware.org/1275/practice/imap/imap0_9d.pdf
|
|
|
|
Additionally to the properties specified in the above standards a host bridge
|
|
driver implementation may support the following properties:
|
|
|
|
- linux,pci-domain:
|
|
If present this property assigns a fixed PCI domain number to a host bridge,
|
|
otherwise an unstable (across boots) unique number will be assigned.
|
|
It is required to either not set this property at all or set it for all
|
|
host bridges in the system, otherwise potentially conflicting domain numbers
|
|
may be assigned to root buses behind different host bridges. The domain
|
|
number for each host bridge in the system must be unique.
|
|
- max-link-speed:
|
|
If present this property specifies PCI gen for link capability. Host
|
|
drivers could add this as a strategy to avoid unnecessary operation for
|
|
unsupported link speed, for instance, trying to do training for
|
|
unsupported link speed, etc. Must be '4' for gen4, '3' for gen3, '2'
|
|
for gen2, and '1' for gen1. Any other values are invalid.
|